function h=CBW_draw_board(G)
N=G.N_Size;
hold on;
global Board
for x=1:N+1,
  h=plot([x;x]-0.5,[1;N+1]-0.5,'b-');
end;
for y=1:N+1,
  h=plot([1;N+1]-0.5,[y;y]-0.5,'b-');
end;
h=[];
m=floor(N/2);
Board(m,m)=1;
Board(m,m+1)=2;
Board(m+1,m)=2;
Board(m+1,m+1)=1;
for x=m:m+1,
    for y=m:m+1,
        show_piece(x,y,Board(x,y));
    end;
end;
